mysql 中查找 \ 删除 作者名字重复 语句

SELECT * FROM author GROUP BY author HAVING COUNT(author)>1

这句会显示 作者重复的记录

SELECT total,`distinct`,total - `distinct` FROM (SELECT COUNT(*) as total,COUNT(DISTINCT(author)) as `distinct` FROM author)  tmp 

这个结果 会 大于/等于  第一句语句的结果

SELECT COUNT(*) FROM author GROUP BY author HAVING COUNT(author)>1   再用这句判断一下 

是因为 重复有可能是重复多次

一次性 删除重复记录

DELETE author AS a FROM  author AS a,(SELECT MIN(id) AS id,author FROM author GROUP BY author HAVING COUNT(author)>1)
 AS b WHERE a.author=b.author AND a.id<>b.id